Left ventricular assist devices are now a therapeutic option in patients with end-stage dilated cardiomyopathy. Existing device are designed for use in severe left ventricular failure. These existing devices have little adaptability for support of the right sided circulation and, in particular, are not well-suited for right ventricular failure. Current device designs also tend to be appropriate for patients with dilated cardiomyopathy, but these devices are not well-suited for use in patients with restrictive cardiomyopathy. Unfortunately, the outcome has been poor for past attempts to existing devices for restrictive cardiomyopathy.
Additionally, further problems with the present generation of devices include the risk of thrombus formation and the risk of infection, as well as negative effects of non-physiologic (non-pulsatile) flow. Non-physiologic flow can potentially cause a number of side-effects, including a high prevalence of gastrointestinal and/or cerebral bleeding. The etiology of the gastrointestinal bleeding is in part related to the non-physiologic flow, and may also be related to the depletion of clotting factors within the blood which may be destroyed by such a non-physiologic assist device. Some existing devices are known to have a 30% incidence of clotting factor depletion.
Current devices also may be difficult to use in the setting of an acute myocardial infarction. In such a situation, the freshly infarcted myocardial tissue may be friable, particularly if the location is apical or anterior. Consequently, use of existing devices may not be feasible because of the apical placement of the inflow cannula.